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xhci: prevent bus suspend if a roothub port detected a over-current condition
[linux/fpc-iii.git] / net / sctp / sm_sideeffect.c
blob0234a64b3b19fc65d031597039a7dd18d8c35973
1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 *
6 * This file is part of the SCTP kernel implementation
7 *
8 * These functions work with the state functions in sctp_sm_statefuns.c
9 * to implement that state operations. These functions implement the
10 * steps which require modifying existing data structures.
11 *
12 * This SCTP implementation is free software;
13 * you can redistribute it and/or modify it under the terms of
14 * the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
16 * any later version.
17 *
18 * This SCTP implementation is distributed in the hope that it
19 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, see
26 * <http://www.gnu.org/licenses/>.
27 *
28 * Please send any bug reports or fixes you make to the
29 * email address(es):
30 * lksctp developers <linux-sctp@vger.kernel.org>
31 *
32 * Written or modified by:
33 * La Monte H.P. Yarroll <piggy@acm.org>
34 * Karl Knutson <karl@athena.chicago.il.us>
35 * Jon Grimm <jgrimm@austin.ibm.com>
36 * Hui Huang <hui.huang@nokia.com>
37 * Dajiang Zhang <dajiang.zhang@nokia.com>
38 * Daisy Chang <daisyc@us.ibm.com>
39 * Sridhar Samudrala <sri@us.ibm.com>
40 * Ardelle Fan <ardelle.fan@intel.com>
41 */
42
43 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
44
45 #include <linux/skbuff.h>
46 #include <linux/types.h>
47 #include <linux/socket.h>
48 #include <linux/ip.h>
49 #include <linux/gfp.h>
50 #include <net/sock.h>
51 #include <net/sctp/sctp.h>
52 #include <net/sctp/sm.h>
53 #include <net/sctp/stream_sched.h>
54
55 static int sctp_cmd_interpreter(enum sctp_event event_type,
56 union sctp_subtype subtype,
57 enum sctp_state state,
58 struct sctp_endpoint *ep,
59 struct sctp_association *asoc,
60 void *event_arg,
61 enum sctp_disposition status,
62 struct sctp_cmd_seq *commands,
63 gfp_t gfp);
64 static int sctp_side_effects(enum sctp_event event_type,
65 union sctp_subtype subtype,
66 enum sctp_state state,
67 struct sctp_endpoint *ep,
68 struct sctp_association **asoc,
69 void *event_arg,
70 enum sctp_disposition status,
71 struct sctp_cmd_seq *commands,
72 gfp_t gfp);
73
74 /********************************************************************
75 * Helper functions
76 ********************************************************************/
77
78 /* A helper function for delayed processing of INET ECN CE bit. */
79 static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
80 __u32 lowest_tsn)
81 {
82 /* Save the TSN away for comparison when we receive CWR */
83
84 asoc->last_ecne_tsn = lowest_tsn;
85 asoc->need_ecne = 1;
86 }
87
88 /* Helper function for delayed processing of SCTP ECNE chunk. */
89 /* RFC 2960 Appendix A
90 *
91 * RFC 2481 details a specific bit for a sender to send in
92 * the header of its next outbound TCP segment to indicate to
93 * its peer that it has reduced its congestion window. This
94 * is termed the CWR bit. For SCTP the same indication is made
95 * by including the CWR chunk. This chunk contains one data
96 * element, i.e. the TSN number that was sent in the ECNE chunk.
97 * This element represents the lowest TSN number in the datagram
98 * that was originally marked with the CE bit.
99 */
100 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
101 __u32 lowest_tsn,
102 struct sctp_chunk *chunk)
103 {
104 struct sctp_chunk *repl;
105
106 /* Our previously transmitted packet ran into some congestion
107 * so we should take action by reducing cwnd and ssthresh
108 * and then ACK our peer that we we've done so by
109 * sending a CWR.
110 */
111
112 /* First, try to determine if we want to actually lower
113 * our cwnd variables. Only lower them if the ECNE looks more
114 * recent than the last response.
115 */
116 if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
117 struct sctp_transport *transport;
118
119 /* Find which transport's congestion variables
120 * need to be adjusted.
121 */
122 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
123
124 /* Update the congestion variables. */
125 if (transport)
126 sctp_transport_lower_cwnd(transport,
127 SCTP_LOWER_CWND_ECNE);
128 asoc->last_cwr_tsn = lowest_tsn;
129 }
130
131 /* Always try to quiet the other end. In case of lost CWR,
132 * resend last_cwr_tsn.
133 */
134 repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
135
136 /* If we run out of memory, it will look like a lost CWR. We'll
137 * get back in sync eventually.
138 */
139 return repl;
140 }
141
142 /* Helper function to do delayed processing of ECN CWR chunk. */
143 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
144 __u32 lowest_tsn)
145 {
146 /* Turn off ECNE getting auto-prepended to every outgoing
147 * packet
148 */
149 asoc->need_ecne = 0;
150 }
151
152 /* Generate SACK if necessary. We call this at the end of a packet. */
153 static int sctp_gen_sack(struct sctp_association *asoc, int force,
154 struct sctp_cmd_seq *commands)
155 {
156 struct sctp_transport *trans = asoc->peer.last_data_from;
157 __u32 ctsn, max_tsn_seen;
158 struct sctp_chunk *sack;
159 int error = 0;
160
161 if (force ||
162 (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
163 (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
164 asoc->peer.sack_needed = 1;
165
166 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
167 max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
168
169 /* From 12.2 Parameters necessary per association (i.e. the TCB):
170 *
171 * Ack State : This flag indicates if the next received packet
172 * : is to be responded to with a SACK. ...
173 * : When DATA chunks are out of order, SACK's
174 * : are not delayed (see Section 6).
175 *
176 * [This is actually not mentioned in Section 6, but we
177 * implement it here anyway. --piggy]
178 */
179 if (max_tsn_seen != ctsn)
180 asoc->peer.sack_needed = 1;
181
182 /* From 6.2 Acknowledgement on Reception of DATA Chunks:
183 *
184 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
185 * an acknowledgement SHOULD be generated for at least every
186 * second packet (not every second DATA chunk) received, and
187 * SHOULD be generated within 200 ms of the arrival of any
188 * unacknowledged DATA chunk. ...
189 */
190 if (!asoc->peer.sack_needed) {
191 asoc->peer.sack_cnt++;
192
193 /* Set the SACK delay timeout based on the
194 * SACK delay for the last transport
195 * data was received from, or the default
196 * for the association.
197 */
198 if (trans) {
199 /* We will need a SACK for the next packet. */
200 if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
201 asoc->peer.sack_needed = 1;
202
203 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
204 trans->sackdelay;
205 } else {
206 /* We will need a SACK for the next packet. */
207 if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
208 asoc->peer.sack_needed = 1;
209
210 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
211 asoc->sackdelay;
212 }
213
214 /* Restart the SACK timer. */
215 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
216 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
217 } else {
218 __u32 old_a_rwnd = asoc->a_rwnd;
219
220 asoc->a_rwnd = asoc->rwnd;
221 sack = sctp_make_sack(asoc);
222 if (!sack) {
223 asoc->a_rwnd = old_a_rwnd;
224 goto nomem;
225 }
226
227 asoc->peer.sack_needed = 0;
228 asoc->peer.sack_cnt = 0;
229
230 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
231
232 /* Stop the SACK timer. */
233 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
234 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
235 }
236
237 return error;
238 nomem:
239 error = -ENOMEM;
240 return error;
241 }
242
243 /* When the T3-RTX timer expires, it calls this function to create the
244 * relevant state machine event.
245 */
246 void sctp_generate_t3_rtx_event(struct timer_list *t)
247 {
248 struct sctp_transport *transport =
249 from_timer(transport, t, T3_rtx_timer);
250 struct sctp_association *asoc = transport->asoc;
251 struct sock *sk = asoc->base.sk;
252 struct net *net = sock_net(sk);
253 int error;
254
255 /* Check whether a task is in the sock. */
256
257 bh_lock_sock(sk);
258 if (sock_owned_by_user(sk)) {
259 pr_debug("%s: sock is busy\n", __func__);
260
261 /* Try again later. */
262 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
263 sctp_transport_hold(transport);
264 goto out_unlock;
265 }
266
267 /* Run through the state machine. */
268 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
269 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
270 asoc->state,
271 asoc->ep, asoc,
272 transport, GFP_ATOMIC);
273
274 if (error)
275 sk->sk_err = -error;
276
277 out_unlock:
278 bh_unlock_sock(sk);
279 sctp_transport_put(transport);
280 }
281
282 /* This is a sa interface for producing timeout events. It works
283 * for timeouts which use the association as their parameter.
284 */
285 static void sctp_generate_timeout_event(struct sctp_association *asoc,
286 enum sctp_event_timeout timeout_type)
287 {
288 struct sock *sk = asoc->base.sk;
289 struct net *net = sock_net(sk);
290 int error = 0;
291
292 bh_lock_sock(sk);
293 if (sock_owned_by_user(sk)) {
294 pr_debug("%s: sock is busy: timer %d\n", __func__,
295 timeout_type);
296
297 /* Try again later. */
298 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
299 sctp_association_hold(asoc);
300 goto out_unlock;
301 }
302
303 /* Is this association really dead and just waiting around for
304 * the timer to let go of the reference?
305 */
306 if (asoc->base.dead)
307 goto out_unlock;
308
309 /* Run through the state machine. */
310 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
311 SCTP_ST_TIMEOUT(timeout_type),
312 asoc->state, asoc->ep, asoc,
313 (void *)timeout_type, GFP_ATOMIC);
314
315 if (error)
316 sk->sk_err = -error;
317
318 out_unlock:
319 bh_unlock_sock(sk);
320 sctp_association_put(asoc);
321 }
322
323 static void sctp_generate_t1_cookie_event(struct timer_list *t)
324 {
325 struct sctp_association *asoc =
326 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
327
328 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
329 }
330
331 static void sctp_generate_t1_init_event(struct timer_list *t)
332 {
333 struct sctp_association *asoc =
334 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T1_INIT]);
335
336 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
337 }
338
339 static void sctp_generate_t2_shutdown_event(struct timer_list *t)
340 {
341 struct sctp_association *asoc =
342 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN]);
343
344 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
345 }
346
347 static void sctp_generate_t4_rto_event(struct timer_list *t)
348 {
349 struct sctp_association *asoc =
350 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T4_RTO]);
351
352 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
353 }
354
355 static void sctp_generate_t5_shutdown_guard_event(struct timer_list *t)
356 {
357 struct sctp_association *asoc =
358 from_timer(asoc, t,
359 timers[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]);
360
361 sctp_generate_timeout_event(asoc,
362 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
363
364 } /* sctp_generate_t5_shutdown_guard_event() */
365
366 static void sctp_generate_autoclose_event(struct timer_list *t)
367 {
368 struct sctp_association *asoc =
369 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_AUTOCLOSE]);
370
371 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
372 }
373
374 /* Generate a heart beat event. If the sock is busy, reschedule. Make
375 * sure that the transport is still valid.
376 */
377 void sctp_generate_heartbeat_event(struct timer_list *t)
378 {
379 struct sctp_transport *transport = from_timer(transport, t, hb_timer);
380 struct sctp_association *asoc = transport->asoc;
381 struct sock *sk = asoc->base.sk;
382 struct net *net = sock_net(sk);
383 u32 elapsed, timeout;
384 int error = 0;
385
386 bh_lock_sock(sk);
387 if (sock_owned_by_user(sk)) {
388 pr_debug("%s: sock is busy\n", __func__);
389
390 /* Try again later. */
391 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
392 sctp_transport_hold(transport);
393 goto out_unlock;
394 }
395
396 /* Check if we should still send the heartbeat or reschedule */
397 elapsed = jiffies - transport->last_time_sent;
398 timeout = sctp_transport_timeout(transport);
399 if (elapsed < timeout) {
400 elapsed = timeout - elapsed;
401 if (!mod_timer(&transport->hb_timer, jiffies + elapsed))
402 sctp_transport_hold(transport);
403 goto out_unlock;
404 }
405
406 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
407 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
408 asoc->state, asoc->ep, asoc,
409 transport, GFP_ATOMIC);
410
411 if (error)
412 sk->sk_err = -error;
413
414 out_unlock:
415 bh_unlock_sock(sk);
416 sctp_transport_put(transport);
417 }
418
419 /* Handle the timeout of the ICMP protocol unreachable timer. Trigger
420 * the correct state machine transition that will close the association.
421 */
422 void sctp_generate_proto_unreach_event(struct timer_list *t)
423 {
424 struct sctp_transport *transport =
425 from_timer(transport, t, proto_unreach_timer);
426 struct sctp_association *asoc = transport->asoc;
427 struct sock *sk = asoc->base.sk;
428 struct net *net = sock_net(sk);
429
430 bh_lock_sock(sk);
431 if (sock_owned_by_user(sk)) {
432 pr_debug("%s: sock is busy\n", __func__);
433
434 /* Try again later. */
435 if (!mod_timer(&transport->proto_unreach_timer,
436 jiffies + (HZ/20)))
437 sctp_association_hold(asoc);
438 goto out_unlock;
439 }
440
441 /* Is this structure just waiting around for us to actually
442 * get destroyed?
443 */
444 if (asoc->base.dead)
445 goto out_unlock;
446
447 sctp_do_sm(net, SCTP_EVENT_T_OTHER,
448 SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
449 asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
450
451 out_unlock:
452 bh_unlock_sock(sk);
453 sctp_association_put(asoc);
454 }
455
456 /* Handle the timeout of the RE-CONFIG timer. */
457 void sctp_generate_reconf_event(struct timer_list *t)
458 {
459 struct sctp_transport *transport =
460 from_timer(transport, t, reconf_timer);
461 struct sctp_association *asoc = transport->asoc;
462 struct sock *sk = asoc->base.sk;
463 struct net *net = sock_net(sk);
464 int error = 0;
465
466 bh_lock_sock(sk);
467 if (sock_owned_by_user(sk)) {
468 pr_debug("%s: sock is busy\n", __func__);
469
470 /* Try again later. */
471 if (!mod_timer(&transport->reconf_timer, jiffies + (HZ / 20)))
472 sctp_transport_hold(transport);
473 goto out_unlock;
474 }
475
476 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
477 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_RECONF),
478 asoc->state, asoc->ep, asoc,
479 transport, GFP_ATOMIC);
480
481 if (error)
482 sk->sk_err = -error;
483
484 out_unlock:
485 bh_unlock_sock(sk);
486 sctp_transport_put(transport);
487 }
488
489 /* Inject a SACK Timeout event into the state machine. */
490 static void sctp_generate_sack_event(struct timer_list *t)
491 {
492 struct sctp_association *asoc =
493 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_SACK]);
494
495 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
496 }
497
498 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
499 [SCTP_EVENT_TIMEOUT_NONE] = NULL,
500 [SCTP_EVENT_TIMEOUT_T1_COOKIE] = sctp_generate_t1_cookie_event,
501 [SCTP_EVENT_TIMEOUT_T1_INIT] = sctp_generate_t1_init_event,
502 [SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = sctp_generate_t2_shutdown_event,
503 [SCTP_EVENT_TIMEOUT_T3_RTX] = NULL,
504 [SCTP_EVENT_TIMEOUT_T4_RTO] = sctp_generate_t4_rto_event,
505 [SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD] =
506 sctp_generate_t5_shutdown_guard_event,
507 [SCTP_EVENT_TIMEOUT_HEARTBEAT] = NULL,
508 [SCTP_EVENT_TIMEOUT_RECONF] = NULL,
509 [SCTP_EVENT_TIMEOUT_SACK] = sctp_generate_sack_event,
510 [SCTP_EVENT_TIMEOUT_AUTOCLOSE] = sctp_generate_autoclose_event,
511 };
512
513
514 /* RFC 2960 8.2 Path Failure Detection
515 *
516 * When its peer endpoint is multi-homed, an endpoint should keep a
517 * error counter for each of the destination transport addresses of the
518 * peer endpoint.
519 *
520 * Each time the T3-rtx timer expires on any address, or when a
521 * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
522 * the error counter of that destination address will be incremented.
523 * When the value in the error counter exceeds the protocol parameter
524 * 'Path.Max.Retrans' of that destination address, the endpoint should
525 * mark the destination transport address as inactive, and a
526 * notification SHOULD be sent to the upper layer.
527 *
528 */
529 static void sctp_do_8_2_transport_strike(struct sctp_cmd_seq *commands,
530 struct sctp_association *asoc,
531 struct sctp_transport *transport,
532 int is_hb)
533 {
534 struct net *net = sock_net(asoc->base.sk);
535
536 /* The check for association's overall error counter exceeding the
537 * threshold is done in the state function.
538 */
539 /* We are here due to a timer expiration. If the timer was
540 * not a HEARTBEAT, then normal error tracking is done.
541 * If the timer was a heartbeat, we only increment error counts
542 * when we already have an outstanding HEARTBEAT that has not
543 * been acknowledged.
544 * Additionally, some tranport states inhibit error increments.
545 */
546 if (!is_hb) {
547 asoc->overall_error_count++;
548 if (transport->state != SCTP_INACTIVE)
549 transport->error_count++;
550 } else if (transport->hb_sent) {
551 if (transport->state != SCTP_UNCONFIRMED)
552 asoc->overall_error_count++;
553 if (transport->state != SCTP_INACTIVE)
554 transport->error_count++;
555 }
556
557 /* If the transport error count is greater than the pf_retrans
558 * threshold, and less than pathmaxrtx, and if the current state
559 * is SCTP_ACTIVE, then mark this transport as Partially Failed,
560 * see SCTP Quick Failover Draft, section 5.1
561 */
562 if (net->sctp.pf_enable &&
563 (transport->state == SCTP_ACTIVE) &&
564 (transport->error_count < transport->pathmaxrxt) &&
565 (transport->error_count > transport->pf_retrans)) {
566
567 sctp_assoc_control_transport(asoc, transport,
568 SCTP_TRANSPORT_PF,
569 0);
570
571 /* Update the hb timer to resend a heartbeat every rto */
572 sctp_transport_reset_hb_timer(transport);
573 }
574
575 if (transport->state != SCTP_INACTIVE &&
576 (transport->error_count > transport->pathmaxrxt)) {
577 pr_debug("%s: association:%p transport addr:%pISpc failed\n",
578 __func__, asoc, &transport->ipaddr.sa);
579
580 sctp_assoc_control_transport(asoc, transport,
581 SCTP_TRANSPORT_DOWN,
582 SCTP_FAILED_THRESHOLD);
583 }
584
585 /* E2) For the destination address for which the timer
586 * expires, set RTO <- RTO * 2 ("back off the timer"). The
587 * maximum value discussed in rule C7 above (RTO.max) may be
588 * used to provide an upper bound to this doubling operation.
589 *
590 * Special Case: the first HB doesn't trigger exponential backoff.
591 * The first unacknowledged HB triggers it. We do this with a flag
592 * that indicates that we have an outstanding HB.
593 */
594 if (!is_hb || transport->hb_sent) {
595 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
596 sctp_max_rto(asoc, transport);
597 }
598 }
599
600 /* Worker routine to handle INIT command failure. */
601 static void sctp_cmd_init_failed(struct sctp_cmd_seq *commands,
602 struct sctp_association *asoc,
603 unsigned int error)
604 {
605 struct sctp_ulpevent *event;
606
607 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_CANT_STR_ASSOC,
608 (__u16)error, 0, 0, NULL,
609 GFP_ATOMIC);
610
611 if (event)
612 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
613 SCTP_ULPEVENT(event));
614
615 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
616 SCTP_STATE(SCTP_STATE_CLOSED));
617
618 /* SEND_FAILED sent later when cleaning up the association. */
619 asoc->outqueue.error = error;
620 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
621 }
622
623 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED. */
624 static void sctp_cmd_assoc_failed(struct sctp_cmd_seq *commands,
625 struct sctp_association *asoc,
626 enum sctp_event event_type,
627 union sctp_subtype subtype,
628 struct sctp_chunk *chunk,
629 unsigned int error)
630 {
631 struct sctp_ulpevent *event;
632 struct sctp_chunk *abort;
633
634 /* Cancel any partial delivery in progress. */
635 asoc->stream.si->abort_pd(&asoc->ulpq, GFP_ATOMIC);
636
637 if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
638 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
639 (__u16)error, 0, 0, chunk,
640 GFP_ATOMIC);
641 else
642 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
643 (__u16)error, 0, 0, NULL,
644 GFP_ATOMIC);
645 if (event)
646 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
647 SCTP_ULPEVENT(event));
648
649 if (asoc->overall_error_count >= asoc->max_retrans) {
650 abort = sctp_make_violation_max_retrans(asoc, chunk);
651 if (abort)
652 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
653 SCTP_CHUNK(abort));
654 }
655
656 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
657 SCTP_STATE(SCTP_STATE_CLOSED));
658
659 /* SEND_FAILED sent later when cleaning up the association. */
660 asoc->outqueue.error = error;
661 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
662 }
663
664 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
665 * inside the cookie. In reality, this is only used for INIT-ACK processing
666 * since all other cases use "temporary" associations and can do all
667 * their work in statefuns directly.
668 */
669 static int sctp_cmd_process_init(struct sctp_cmd_seq *commands,
670 struct sctp_association *asoc,
671 struct sctp_chunk *chunk,
672 struct sctp_init_chunk *peer_init,
673 gfp_t gfp)
674 {
675 int error;
676
677 /* We only process the init as a sideeffect in a single
678 * case. This is when we process the INIT-ACK. If we
679 * fail during INIT processing (due to malloc problems),
680 * just return the error and stop processing the stack.
681 */
682 if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
683 error = -ENOMEM;
684 else
685 error = 0;
686
687 return error;
688 }
689
690 /* Helper function to break out starting up of heartbeat timers. */
691 static void sctp_cmd_hb_timers_start(struct sctp_cmd_seq *cmds,
692 struct sctp_association *asoc)
693 {
694 struct sctp_transport *t;
695
696 /* Start a heartbeat timer for each transport on the association.
697 * hold a reference on the transport to make sure none of
698 * the needed data structures go away.
699 */
700 list_for_each_entry(t, &asoc->peer.transport_addr_list, transports)
701 sctp_transport_reset_hb_timer(t);
702 }
703
704 static void sctp_cmd_hb_timers_stop(struct sctp_cmd_seq *cmds,
705 struct sctp_association *asoc)
706 {
707 struct sctp_transport *t;
708
709 /* Stop all heartbeat timers. */
710
711 list_for_each_entry(t, &asoc->peer.transport_addr_list,
712 transports) {
713 if (del_timer(&t->hb_timer))
714 sctp_transport_put(t);
715 }
716 }
717
718 /* Helper function to stop any pending T3-RTX timers */
719 static void sctp_cmd_t3_rtx_timers_stop(struct sctp_cmd_seq *cmds,
720 struct sctp_association *asoc)
721 {
722 struct sctp_transport *t;
723
724 list_for_each_entry(t, &asoc->peer.transport_addr_list,
725 transports) {
726 if (del_timer(&t->T3_rtx_timer))
727 sctp_transport_put(t);
728 }
729 }
730
731
732 /* Helper function to handle the reception of an HEARTBEAT ACK. */
733 static void sctp_cmd_transport_on(struct sctp_cmd_seq *cmds,
734 struct sctp_association *asoc,
735 struct sctp_transport *t,
736 struct sctp_chunk *chunk)
737 {
738 struct sctp_sender_hb_info *hbinfo;
739 int was_unconfirmed = 0;
740
741 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
742 * HEARTBEAT should clear the error counter of the destination
743 * transport address to which the HEARTBEAT was sent.
744 */
745 t->error_count = 0;
746
747 /*
748 * Although RFC4960 specifies that the overall error count must
749 * be cleared when a HEARTBEAT ACK is received, we make an
750 * exception while in SHUTDOWN PENDING. If the peer keeps its
751 * window shut forever, we may never be able to transmit our
752 * outstanding data and rely on the retransmission limit be reached
753 * to shutdown the association.
754 */
755 if (t->asoc->state < SCTP_STATE_SHUTDOWN_PENDING)
756 t->asoc->overall_error_count = 0;
757
758 /* Clear the hb_sent flag to signal that we had a good
759 * acknowledgement.
760 */
761 t->hb_sent = 0;
762
763 /* Mark the destination transport address as active if it is not so
764 * marked.
765 */
766 if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) {
767 was_unconfirmed = 1;
768 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
769 SCTP_HEARTBEAT_SUCCESS);
770 }
771
772 if (t->state == SCTP_PF)
773 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
774 SCTP_HEARTBEAT_SUCCESS);
775
776 /* HB-ACK was received for a the proper HB. Consider this
777 * forward progress.
778 */
779 if (t->dst)
780 sctp_transport_dst_confirm(t);
781
782 /* The receiver of the HEARTBEAT ACK should also perform an
783 * RTT measurement for that destination transport address
784 * using the time value carried in the HEARTBEAT ACK chunk.
785 * If the transport's rto_pending variable has been cleared,
786 * it was most likely due to a retransmit. However, we want
787 * to re-enable it to properly update the rto.
788 */
789 if (t->rto_pending == 0)
790 t->rto_pending = 1;
791
792 hbinfo = (struct sctp_sender_hb_info *)chunk->skb->data;
793 sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
794
795 /* Update the heartbeat timer. */
796 sctp_transport_reset_hb_timer(t);
797
798 if (was_unconfirmed && asoc->peer.transport_count == 1)
799 sctp_transport_immediate_rtx(t);
800 }
801
802
803 /* Helper function to process the process SACK command. */
804 static int sctp_cmd_process_sack(struct sctp_cmd_seq *cmds,
805 struct sctp_association *asoc,
806 struct sctp_chunk *chunk)
807 {
808 int err = 0;
809
810 if (sctp_outq_sack(&asoc->outqueue, chunk)) {
811 struct net *net = sock_net(asoc->base.sk);
812
813 /* There are no more TSNs awaiting SACK. */
814 err = sctp_do_sm(net, SCTP_EVENT_T_OTHER,
815 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
816 asoc->state, asoc->ep, asoc, NULL,
817 GFP_ATOMIC);
818 }
819
820 return err;
821 }
822
823 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
824 * the transport for a shutdown chunk.
825 */
826 static void sctp_cmd_setup_t2(struct sctp_cmd_seq *cmds,
827 struct sctp_association *asoc,
828 struct sctp_chunk *chunk)
829 {
830 struct sctp_transport *t;
831
832 if (chunk->transport)
833 t = chunk->transport;
834 else {
835 t = sctp_assoc_choose_alter_transport(asoc,
836 asoc->shutdown_last_sent_to);
837 chunk->transport = t;
838 }
839 asoc->shutdown_last_sent_to = t;
840 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
841 }
842
843 static void sctp_cmd_assoc_update(struct sctp_cmd_seq *cmds,
844 struct sctp_association *asoc,
845 struct sctp_association *new)
846 {
847 struct net *net = sock_net(asoc->base.sk);
848 struct sctp_chunk *abort;
849
850 if (!sctp_assoc_update(asoc, new))
851 return;
852
853 abort = sctp_make_abort(asoc, NULL, sizeof(struct sctp_errhdr));
854 if (abort) {
855 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
856 sctp_add_cmd_sf(cmds, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
857 }
858 sctp_add_cmd_sf(cmds, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNABORTED));
859 sctp_add_cmd_sf(cmds, SCTP_CMD_ASSOC_FAILED,
860 SCTP_PERR(SCTP_ERROR_RSRC_LOW));
861 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
862 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
863 }
864
865 /* Helper function to change the state of an association. */
866 static void sctp_cmd_new_state(struct sctp_cmd_seq *cmds,
867 struct sctp_association *asoc,
868 enum sctp_state state)
869 {
870 struct sock *sk = asoc->base.sk;
871
872 asoc->state = state;
873
874 pr_debug("%s: asoc:%p[%s]\n", __func__, asoc, sctp_state_tbl[state]);
875
876 if (sctp_style(sk, TCP)) {
877 /* Change the sk->sk_state of a TCP-style socket that has
878 * successfully completed a connect() call.
879 */
880 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
881 inet_sk_set_state(sk, SCTP_SS_ESTABLISHED);
882
883 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
884 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
885 sctp_sstate(sk, ESTABLISHED)) {
886 inet_sk_set_state(sk, SCTP_SS_CLOSING);
887 sk->sk_shutdown |= RCV_SHUTDOWN;
888 }
889 }
890
891 if (sctp_state(asoc, COOKIE_WAIT)) {
892 /* Reset init timeouts since they may have been
893 * increased due to timer expirations.
894 */
895 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
896 asoc->rto_initial;
897 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
898 asoc->rto_initial;
899 }
900
901 if (sctp_state(asoc, ESTABLISHED)) {
902 kfree(asoc->peer.cookie);
903 asoc->peer.cookie = NULL;
904 }
905
906 if (sctp_state(asoc, ESTABLISHED) ||
907 sctp_state(asoc, CLOSED) ||
908 sctp_state(asoc, SHUTDOWN_RECEIVED)) {
909 /* Wake up any processes waiting in the asoc's wait queue in
910 * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
911 */
912 if (waitqueue_active(&asoc->wait))
913 wake_up_interruptible(&asoc->wait);
914
915 /* Wake up any processes waiting in the sk's sleep queue of
916 * a TCP-style or UDP-style peeled-off socket in
917 * sctp_wait_for_accept() or sctp_wait_for_packet().
918 * For a UDP-style socket, the waiters are woken up by the
919 * notifications.
920 */
921 if (!sctp_style(sk, UDP))
922 sk->sk_state_change(sk);
923 }
924
925 if (sctp_state(asoc, SHUTDOWN_PENDING) &&
926 !sctp_outq_is_empty(&asoc->outqueue))
927 sctp_outq_uncork(&asoc->outqueue, GFP_ATOMIC);
928 }
929
930 /* Helper function to delete an association. */
931 static void sctp_cmd_delete_tcb(struct sctp_cmd_seq *cmds,
932 struct sctp_association *asoc)
933 {
934 struct sock *sk = asoc->base.sk;
935
936 /* If it is a non-temporary association belonging to a TCP-style
937 * listening socket that is not closed, do not free it so that accept()
938 * can pick it up later.
939 */
940 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
941 (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
942 return;
943
944 sctp_association_free(asoc);
945 }
946
947 /*
948 * ADDIP Section 4.1 ASCONF Chunk Procedures
949 * A4) Start a T-4 RTO timer, using the RTO value of the selected
950 * destination address (we use active path instead of primary path just
951 * because primary path may be inactive.
952 */
953 static void sctp_cmd_setup_t4(struct sctp_cmd_seq *cmds,
954 struct sctp_association *asoc,
955 struct sctp_chunk *chunk)
956 {
957 struct sctp_transport *t;
958
959 t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
960 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
961 chunk->transport = t;
962 }
963
964 /* Process an incoming Operation Error Chunk. */
965 static void sctp_cmd_process_operr(struct sctp_cmd_seq *cmds,
966 struct sctp_association *asoc,
967 struct sctp_chunk *chunk)
968 {
969 struct sctp_errhdr *err_hdr;
970 struct sctp_ulpevent *ev;
971
972 while (chunk->chunk_end > chunk->skb->data) {
973 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
974
975 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
976 GFP_ATOMIC);
977 if (!ev)
978 return;
979
980 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
981
982 switch (err_hdr->cause) {
983 case SCTP_ERROR_UNKNOWN_CHUNK:
984 {
985 struct sctp_chunkhdr *unk_chunk_hdr;
986
987 unk_chunk_hdr = (struct sctp_chunkhdr *)
988 err_hdr->variable;
989 switch (unk_chunk_hdr->type) {
990 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
991 * an ERROR chunk reporting that it did not recognized
992 * the ASCONF chunk type, the sender of the ASCONF MUST
993 * NOT send any further ASCONF chunks and MUST stop its
994 * T-4 timer.
995 */
996 case SCTP_CID_ASCONF:
997 if (asoc->peer.asconf_capable == 0)
998 break;
999
1000 asoc->peer.asconf_capable = 0;
1001 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
1002 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
1003 break;
1004 default:
1005 break;
1006 }
1007 break;
1008 }
1009 default:
1010 break;
1011 }
1012 }
1013 }
1014
1015 /* Helper function to remove the association non-primary peer
1016 * transports.
1017 */
1018 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
1019 {
1020 struct sctp_transport *t;
1021 struct list_head *temp;
1022 struct list_head *pos;
1023
1024 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1025 t = list_entry(pos, struct sctp_transport, transports);
1026 if (!sctp_cmp_addr_exact(&t->ipaddr,
1027 &asoc->peer.primary_addr)) {
1028 sctp_assoc_rm_peer(asoc, t);
1029 }
1030 }
1031 }
1032
1033 /* Helper function to set sk_err on a 1-1 style socket. */
1034 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
1035 {
1036 struct sock *sk = asoc->base.sk;
1037
1038 if (!sctp_style(sk, UDP))
1039 sk->sk_err = error;
1040 }
1041
1042 /* Helper function to generate an association change event */
1043 static void sctp_cmd_assoc_change(struct sctp_cmd_seq *commands,
1044 struct sctp_association *asoc,
1045 u8 state)
1046 {
1047 struct sctp_ulpevent *ev;
1048
1049 ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
1050 asoc->c.sinit_num_ostreams,
1051 asoc->c.sinit_max_instreams,
1052 NULL, GFP_ATOMIC);
1053 if (ev)
1054 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1055 }
1056
1057 static void sctp_cmd_peer_no_auth(struct sctp_cmd_seq *commands,
1058 struct sctp_association *asoc)
1059 {
1060 struct sctp_ulpevent *ev;
1061
1062 ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH, GFP_ATOMIC);
1063 if (ev)
1064 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1065 }
1066
1067 /* Helper function to generate an adaptation indication event */
1068 static void sctp_cmd_adaptation_ind(struct sctp_cmd_seq *commands,
1069 struct sctp_association *asoc)
1070 {
1071 struct sctp_ulpevent *ev;
1072
1073 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
1074
1075 if (ev)
1076 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1077 }
1078
1079
1080 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
1081 enum sctp_event_timeout timer,
1082 char *name)
1083 {
1084 struct sctp_transport *t;
1085
1086 t = asoc->init_last_sent_to;
1087 asoc->init_err_counter++;
1088
1089 if (t->init_sent_count > (asoc->init_cycle + 1)) {
1090 asoc->timeouts[timer] *= 2;
1091 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
1092 asoc->timeouts[timer] = asoc->max_init_timeo;
1093 }
1094 asoc->init_cycle++;
1095
1096 pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d"
1097 " cycle:%d timeout:%ld\n", __func__, name,
1098 asoc->init_err_counter, asoc->init_cycle,
1099 asoc->timeouts[timer]);
1100 }
1101
1102 }
1103
1104 /* Send the whole message, chunk by chunk, to the outqueue.
1105 * This way the whole message is queued up and bundling if
1106 * encouraged for small fragments.
1107 */
1108 static void sctp_cmd_send_msg(struct sctp_association *asoc,
1109 struct sctp_datamsg *msg, gfp_t gfp)
1110 {
1111 struct sctp_chunk *chunk;
1112
1113 list_for_each_entry(chunk, &msg->chunks, frag_list)
1114 sctp_outq_tail(&asoc->outqueue, chunk, gfp);
1115
1116 asoc->outqueue.sched->enqueue(&asoc->outqueue, msg);
1117 }
1118
1119
1120 /* These three macros allow us to pull the debugging code out of the
1121 * main flow of sctp_do_sm() to keep attention focused on the real
1122 * functionality there.
1123 */
1124 #define debug_pre_sfn() \
1125 pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \
1126 ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype), \
1127 asoc, sctp_state_tbl[state], state_fn->name)
1128
1129 #define debug_post_sfn() \
1130 pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \
1131 sctp_status_tbl[status])
1132
1133 #define debug_post_sfx() \
1134 pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \
1135 asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1136 sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED])
1137
1138 /*
1139 * This is the master state machine processing function.
1140 *
1141 * If you want to understand all of lksctp, this is a
1142 * good place to start.
1143 */
1144 int sctp_do_sm(struct net *net, enum sctp_event event_type,
1145 union sctp_subtype subtype, enum sctp_state state,
1146 struct sctp_endpoint *ep, struct sctp_association *asoc,
1147 void *event_arg, gfp_t gfp)
1148 {
1149 typedef const char *(printfn_t)(union sctp_subtype);
1150 static printfn_t *table[] = {
1151 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1152 };
1153 printfn_t *debug_fn __attribute__ ((unused)) = table[event_type];
1154 const struct sctp_sm_table_entry *state_fn;
1155 struct sctp_cmd_seq commands;
1156 enum sctp_disposition status;
1157 int error = 0;
1158
1159 /* Look up the state function, run it, and then process the
1160 * side effects. These three steps are the heart of lksctp.
1161 */
1162 state_fn = sctp_sm_lookup_event(net, event_type, state, subtype);
1163
1164 sctp_init_cmd_seq(&commands);
1165
1166 debug_pre_sfn();
1167 status = state_fn->fn(net, ep, asoc, subtype, event_arg, &commands);
1168 debug_post_sfn();
1169
1170 error = sctp_side_effects(event_type, subtype, state,
1171 ep, &asoc, event_arg, status,
1172 &commands, gfp);
1173 debug_post_sfx();
1174
1175 return error;
1176 }
1177
1178 /*****************************************************************
1179 * This the master state function side effect processing function.
1180 *****************************************************************/
1181 static int sctp_side_effects(enum sctp_event event_type,
1182 union sctp_subtype subtype,
1183 enum sctp_state state,
1184 struct sctp_endpoint *ep,
1185 struct sctp_association **asoc,
1186 void *event_arg,
1187 enum sctp_disposition status,
1188 struct sctp_cmd_seq *commands,
1189 gfp_t gfp)
1190 {
1191 int error;
1192
1193 /* FIXME - Most of the dispositions left today would be categorized
1194 * as "exceptional" dispositions. For those dispositions, it
1195 * may not be proper to run through any of the commands at all.
1196 * For example, the command interpreter might be run only with
1197 * disposition SCTP_DISPOSITION_CONSUME.
1198 */
1199 if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1200 ep, *asoc,
1201 event_arg, status,
1202 commands, gfp)))
1203 goto bail;
1204
1205 switch (status) {
1206 case SCTP_DISPOSITION_DISCARD:
1207 pr_debug("%s: ignored sctp protocol event - state:%d, "
1208 "event_type:%d, event_id:%d\n", __func__, state,
1209 event_type, subtype.chunk);
1210 break;
1211
1212 case SCTP_DISPOSITION_NOMEM:
1213 /* We ran out of memory, so we need to discard this
1214 * packet.
1215 */
1216 /* BUG--we should now recover some memory, probably by
1217 * reneging...
1218 */
1219 error = -ENOMEM;
1220 break;
1221
1222 case SCTP_DISPOSITION_DELETE_TCB:
1223 case SCTP_DISPOSITION_ABORT:
1224 /* This should now be a command. */
1225 *asoc = NULL;
1226 break;
1227
1228 case SCTP_DISPOSITION_CONSUME:
1229 /*
1230 * We should no longer have much work to do here as the
1231 * real work has been done as explicit commands above.
1232 */
1233 break;
1234
1235 case SCTP_DISPOSITION_VIOLATION:
1236 net_err_ratelimited("protocol violation state %d chunkid %d\n",
1237 state, subtype.chunk);
1238 break;
1239
1240 case SCTP_DISPOSITION_NOT_IMPL:
1241 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1242 state, event_type, subtype.chunk);
1243 break;
1244
1245 case SCTP_DISPOSITION_BUG:
1246 pr_err("bug in state %d, event_type %d, event_id %d\n",
1247 state, event_type, subtype.chunk);
1248 BUG();
1249 break;
1250
1251 default:
1252 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1253 status, state, event_type, subtype.chunk);
1254 BUG();
1255 break;
1256 }
1257
1258 bail:
1259 return error;
1260 }
1261
1262 /********************************************************************
1263 * 2nd Level Abstractions
1264 ********************************************************************/
1265
1266 /* This is the side-effect interpreter. */
1267 static int sctp_cmd_interpreter(enum sctp_event event_type,
1268 union sctp_subtype subtype,
1269 enum sctp_state state,
1270 struct sctp_endpoint *ep,
1271 struct sctp_association *asoc,
1272 void *event_arg,
1273 enum sctp_disposition status,
1274 struct sctp_cmd_seq *commands,
1275 gfp_t gfp)
1276 {
1277 struct sctp_sock *sp = sctp_sk(ep->base.sk);
1278 struct sctp_chunk *chunk = NULL, *new_obj;
1279 struct sctp_packet *packet;
1280 struct sctp_sackhdr sackh;
1281 struct timer_list *timer;
1282 struct sctp_transport *t;
1283 unsigned long timeout;
1284 struct sctp_cmd *cmd;
1285 int local_cork = 0;
1286 int error = 0;
1287 int force;
1288
1289 if (SCTP_EVENT_T_TIMEOUT != event_type)
1290 chunk = event_arg;
1291
1292 /* Note: This whole file is a huge candidate for rework.
1293 * For example, each command could either have its own handler, so
1294 * the loop would look like:
1295 * while (cmds)
1296 * cmd->handle(x, y, z)
1297 * --jgrimm
1298 */
1299 while (NULL != (cmd = sctp_next_cmd(commands))) {
1300 switch (cmd->verb) {
1301 case SCTP_CMD_NOP:
1302 /* Do nothing. */
1303 break;
1304
1305 case SCTP_CMD_NEW_ASOC:
1306 /* Register a new association. */
1307 if (local_cork) {
1308 sctp_outq_uncork(&asoc->outqueue, gfp);
1309 local_cork = 0;
1310 }
1311
1312 /* Register with the endpoint. */
1313 asoc = cmd->obj.asoc;
1314 BUG_ON(asoc->peer.primary_path == NULL);
1315 sctp_endpoint_add_asoc(ep, asoc);
1316 break;
1317
1318 case SCTP_CMD_UPDATE_ASSOC:
1319 sctp_cmd_assoc_update(commands, asoc, cmd->obj.asoc);
1320 break;
1321
1322 case SCTP_CMD_PURGE_OUTQUEUE:
1323 sctp_outq_teardown(&asoc->outqueue);
1324 break;
1325
1326 case SCTP_CMD_DELETE_TCB:
1327 if (local_cork) {
1328 sctp_outq_uncork(&asoc->outqueue, gfp);
1329 local_cork = 0;
1330 }
1331 /* Delete the current association. */
1332 sctp_cmd_delete_tcb(commands, asoc);
1333 asoc = NULL;
1334 break;
1335
1336 case SCTP_CMD_NEW_STATE:
1337 /* Enter a new state. */
1338 sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1339 break;
1340
1341 case SCTP_CMD_REPORT_TSN:
1342 /* Record the arrival of a TSN. */
1343 error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1344 cmd->obj.u32, NULL);
1345 break;
1346
1347 case SCTP_CMD_REPORT_FWDTSN:
1348 asoc->stream.si->report_ftsn(&asoc->ulpq, cmd->obj.u32);
1349 break;
1350
1351 case SCTP_CMD_PROCESS_FWDTSN:
1352 asoc->stream.si->handle_ftsn(&asoc->ulpq,
1353 cmd->obj.chunk);
1354 break;
1355
1356 case SCTP_CMD_GEN_SACK:
1357 /* Generate a Selective ACK.
1358 * The argument tells us whether to just count
1359 * the packet and MAYBE generate a SACK, or
1360 * force a SACK out.
1361 */
1362 force = cmd->obj.i32;
1363 error = sctp_gen_sack(asoc, force, commands);
1364 break;
1365
1366 case SCTP_CMD_PROCESS_SACK:
1367 /* Process an inbound SACK. */
1368 error = sctp_cmd_process_sack(commands, asoc,
1369 cmd->obj.chunk);
1370 break;
1371
1372 case SCTP_CMD_GEN_INIT_ACK:
1373 /* Generate an INIT ACK chunk. */
1374 new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1375 0);
1376 if (!new_obj) {
1377 error = -ENOMEM;
1378 break;
1379 }
1380
1381 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1382 SCTP_CHUNK(new_obj));
1383 break;
1384
1385 case SCTP_CMD_PEER_INIT:
1386 /* Process a unified INIT from the peer.
1387 * Note: Only used during INIT-ACK processing. If
1388 * there is an error just return to the outter
1389 * layer which will bail.
1390 */
1391 error = sctp_cmd_process_init(commands, asoc, chunk,
1392 cmd->obj.init, gfp);
1393 break;
1394
1395 case SCTP_CMD_GEN_COOKIE_ECHO:
1396 /* Generate a COOKIE ECHO chunk. */
1397 new_obj = sctp_make_cookie_echo(asoc, chunk);
1398 if (!new_obj) {
1399 if (cmd->obj.chunk)
1400 sctp_chunk_free(cmd->obj.chunk);
1401 error = -ENOMEM;
1402 break;
1403 }
1404 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1405 SCTP_CHUNK(new_obj));
1406
1407 /* If there is an ERROR chunk to be sent along with
1408 * the COOKIE_ECHO, send it, too.
1409 */
1410 if (cmd->obj.chunk)
1411 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1412 SCTP_CHUNK(cmd->obj.chunk));
1413
1414 if (new_obj->transport) {
1415 new_obj->transport->init_sent_count++;
1416 asoc->init_last_sent_to = new_obj->transport;
1417 }
1418
1419 /* FIXME - Eventually come up with a cleaner way to
1420 * enabling COOKIE-ECHO + DATA bundling during
1421 * multihoming stale cookie scenarios, the following
1422 * command plays with asoc->peer.retran_path to
1423 * avoid the problem of sending the COOKIE-ECHO and
1424 * DATA in different paths, which could result
1425 * in the association being ABORTed if the DATA chunk
1426 * is processed first by the server. Checking the
1427 * init error counter simply causes this command
1428 * to be executed only during failed attempts of
1429 * association establishment.
1430 */
1431 if ((asoc->peer.retran_path !=
1432 asoc->peer.primary_path) &&
1433 (asoc->init_err_counter > 0)) {
1434 sctp_add_cmd_sf(commands,
1435 SCTP_CMD_FORCE_PRIM_RETRAN,
1436 SCTP_NULL());
1437 }
1438
1439 break;
1440
1441 case SCTP_CMD_GEN_SHUTDOWN:
1442 /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1443 * Reset error counts.
1444 */
1445 asoc->overall_error_count = 0;
1446
1447 /* Generate a SHUTDOWN chunk. */
1448 new_obj = sctp_make_shutdown(asoc, chunk);
1449 if (!new_obj) {
1450 error = -ENOMEM;
1451 break;
1452 }
1453 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1454 SCTP_CHUNK(new_obj));
1455 break;
1456
1457 case SCTP_CMD_CHUNK_ULP:
1458 /* Send a chunk to the sockets layer. */
1459 pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n",
1460 __func__, cmd->obj.chunk, &asoc->ulpq);
1461
1462 asoc->stream.si->ulpevent_data(&asoc->ulpq,
1463 cmd->obj.chunk,
1464 GFP_ATOMIC);
1465 break;
1466
1467 case SCTP_CMD_EVENT_ULP:
1468 /* Send a notification to the sockets layer. */
1469 pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n",
1470 __func__, cmd->obj.ulpevent, &asoc->ulpq);
1471
1472 asoc->stream.si->enqueue_event(&asoc->ulpq,
1473 cmd->obj.ulpevent);
1474 break;
1475
1476 case SCTP_CMD_REPLY:
1477 /* If an caller has not already corked, do cork. */
1478 if (!asoc->outqueue.cork) {
1479 sctp_outq_cork(&asoc->outqueue);
1480 local_cork = 1;
1481 }
1482 /* Send a chunk to our peer. */
1483 sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk, gfp);
1484 break;
1485
1486 case SCTP_CMD_SEND_PKT:
1487 /* Send a full packet to our peer. */
1488 packet = cmd->obj.packet;
1489 sctp_packet_transmit(packet, gfp);
1490 sctp_ootb_pkt_free(packet);
1491 break;
1492
1493 case SCTP_CMD_T1_RETRAN:
1494 /* Mark a transport for retransmission. */
1495 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1496 SCTP_RTXR_T1_RTX);
1497 break;
1498
1499 case SCTP_CMD_RETRAN:
1500 /* Mark a transport for retransmission. */
1501 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1502 SCTP_RTXR_T3_RTX);
1503 break;
1504
1505 case SCTP_CMD_ECN_CE:
1506 /* Do delayed CE processing. */
1507 sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1508 break;
1509
1510 case SCTP_CMD_ECN_ECNE:
1511 /* Do delayed ECNE processing. */
1512 new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1513 chunk);
1514 if (new_obj)
1515 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1516 SCTP_CHUNK(new_obj));
1517 break;
1518
1519 case SCTP_CMD_ECN_CWR:
1520 /* Do delayed CWR processing. */
1521 sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1522 break;
1523
1524 case SCTP_CMD_SETUP_T2:
1525 sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk);
1526 break;
1527
1528 case SCTP_CMD_TIMER_START_ONCE:
1529 timer = &asoc->timers[cmd->obj.to];
1530
1531 if (timer_pending(timer))
1532 break;
1533 /* fall through */
1534
1535 case SCTP_CMD_TIMER_START:
1536 timer = &asoc->timers[cmd->obj.to];
1537 timeout = asoc->timeouts[cmd->obj.to];
1538 BUG_ON(!timeout);
1539
1540 timer->expires = jiffies + timeout;
1541 sctp_association_hold(asoc);
1542 add_timer(timer);
1543 break;
1544
1545 case SCTP_CMD_TIMER_RESTART:
1546 timer = &asoc->timers[cmd->obj.to];
1547 timeout = asoc->timeouts[cmd->obj.to];
1548 if (!mod_timer(timer, jiffies + timeout))
1549 sctp_association_hold(asoc);
1550 break;
1551
1552 case SCTP_CMD_TIMER_STOP:
1553 timer = &asoc->timers[cmd->obj.to];
1554 if (del_timer(timer))
1555 sctp_association_put(asoc);
1556 break;
1557
1558 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1559 chunk = cmd->obj.chunk;
1560 t = sctp_assoc_choose_alter_transport(asoc,
1561 asoc->init_last_sent_to);
1562 asoc->init_last_sent_to = t;
1563 chunk->transport = t;
1564 t->init_sent_count++;
1565 /* Set the new transport as primary */
1566 sctp_assoc_set_primary(asoc, t);
1567 break;
1568
1569 case SCTP_CMD_INIT_RESTART:
1570 /* Do the needed accounting and updates
1571 * associated with restarting an initialization
1572 * timer. Only multiply the timeout by two if
1573 * all transports have been tried at the current
1574 * timeout.
1575 */
1576 sctp_cmd_t1_timer_update(asoc,
1577 SCTP_EVENT_TIMEOUT_T1_INIT,
1578 "INIT");
1579
1580 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1581 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1582 break;
1583
1584 case SCTP_CMD_COOKIEECHO_RESTART:
1585 /* Do the needed accounting and updates
1586 * associated with restarting an initialization
1587 * timer. Only multiply the timeout by two if
1588 * all transports have been tried at the current
1589 * timeout.
1590 */
1591 sctp_cmd_t1_timer_update(asoc,
1592 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1593 "COOKIE");
1594
1595 /* If we've sent any data bundled with
1596 * COOKIE-ECHO we need to resend.
1597 */
1598 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1599 transports) {
1600 sctp_retransmit_mark(&asoc->outqueue, t,
1601 SCTP_RTXR_T1_RTX);
1602 }
1603
1604 sctp_add_cmd_sf(commands,
1605 SCTP_CMD_TIMER_RESTART,
1606 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1607 break;
1608
1609 case SCTP_CMD_INIT_FAILED:
1610 sctp_cmd_init_failed(commands, asoc, cmd->obj.u32);
1611 break;
1612
1613 case SCTP_CMD_ASSOC_FAILED:
1614 sctp_cmd_assoc_failed(commands, asoc, event_type,
1615 subtype, chunk, cmd->obj.u32);
1616 break;
1617
1618 case SCTP_CMD_INIT_COUNTER_INC:
1619 asoc->init_err_counter++;
1620 break;
1621
1622 case SCTP_CMD_INIT_COUNTER_RESET:
1623 asoc->init_err_counter = 0;
1624 asoc->init_cycle = 0;
1625 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1626 transports) {
1627 t->init_sent_count = 0;
1628 }
1629 break;
1630
1631 case SCTP_CMD_REPORT_DUP:
1632 sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1633 cmd->obj.u32);
1634 break;
1635
1636 case SCTP_CMD_REPORT_BAD_TAG:
1637 pr_debug("%s: vtag mismatch!\n", __func__);
1638 break;
1639
1640 case SCTP_CMD_STRIKE:
1641 /* Mark one strike against a transport. */
1642 sctp_do_8_2_transport_strike(commands, asoc,
1643 cmd->obj.transport, 0);
1644 break;
1645
1646 case SCTP_CMD_TRANSPORT_IDLE:
1647 t = cmd->obj.transport;
1648 sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1649 break;
1650
1651 case SCTP_CMD_TRANSPORT_HB_SENT:
1652 t = cmd->obj.transport;
1653 sctp_do_8_2_transport_strike(commands, asoc,
1654 t, 1);
1655 t->hb_sent = 1;
1656 break;
1657
1658 case SCTP_CMD_TRANSPORT_ON:
1659 t = cmd->obj.transport;
1660 sctp_cmd_transport_on(commands, asoc, t, chunk);
1661 break;
1662
1663 case SCTP_CMD_HB_TIMERS_START:
1664 sctp_cmd_hb_timers_start(commands, asoc);
1665 break;
1666
1667 case SCTP_CMD_HB_TIMER_UPDATE:
1668 t = cmd->obj.transport;
1669 sctp_transport_reset_hb_timer(t);
1670 break;
1671
1672 case SCTP_CMD_HB_TIMERS_STOP:
1673 sctp_cmd_hb_timers_stop(commands, asoc);
1674 break;
1675
1676 case SCTP_CMD_REPORT_ERROR:
1677 error = cmd->obj.error;
1678 break;
1679
1680 case SCTP_CMD_PROCESS_CTSN:
1681 /* Dummy up a SACK for processing. */
1682 sackh.cum_tsn_ack = cmd->obj.be32;
1683 sackh.a_rwnd = htonl(asoc->peer.rwnd +
1684 asoc->outqueue.outstanding_bytes);
1685 sackh.num_gap_ack_blocks = 0;
1686 sackh.num_dup_tsns = 0;
1687 chunk->subh.sack_hdr = &sackh;
1688 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1689 SCTP_CHUNK(chunk));
1690 break;
1691
1692 case SCTP_CMD_DISCARD_PACKET:
1693 /* We need to discard the whole packet.
1694 * Uncork the queue since there might be
1695 * responses pending
1696 */
1697 chunk->pdiscard = 1;
1698 if (asoc) {
1699 sctp_outq_uncork(&asoc->outqueue, gfp);
1700 local_cork = 0;
1701 }
1702 break;
1703
1704 case SCTP_CMD_RTO_PENDING:
1705 t = cmd->obj.transport;
1706 t->rto_pending = 1;
1707 break;
1708
1709 case SCTP_CMD_PART_DELIVER:
1710 asoc->stream.si->start_pd(&asoc->ulpq, GFP_ATOMIC);
1711 break;
1712
1713 case SCTP_CMD_RENEGE:
1714 asoc->stream.si->renege_events(&asoc->ulpq,
1715 cmd->obj.chunk,
1716 GFP_ATOMIC);
1717 break;
1718
1719 case SCTP_CMD_SETUP_T4:
1720 sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk);
1721 break;
1722
1723 case SCTP_CMD_PROCESS_OPERR:
1724 sctp_cmd_process_operr(commands, asoc, chunk);
1725 break;
1726 case SCTP_CMD_CLEAR_INIT_TAG:
1727 asoc->peer.i.init_tag = 0;
1728 break;
1729 case SCTP_CMD_DEL_NON_PRIMARY:
1730 sctp_cmd_del_non_primary(asoc);
1731 break;
1732 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1733 sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1734 break;
1735 case SCTP_CMD_FORCE_PRIM_RETRAN:
1736 t = asoc->peer.retran_path;
1737 asoc->peer.retran_path = asoc->peer.primary_path;
1738 sctp_outq_uncork(&asoc->outqueue, gfp);
1739 local_cork = 0;
1740 asoc->peer.retran_path = t;
1741 break;
1742 case SCTP_CMD_SET_SK_ERR:
1743 sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1744 break;
1745 case SCTP_CMD_ASSOC_CHANGE:
1746 sctp_cmd_assoc_change(commands, asoc,
1747 cmd->obj.u8);
1748 break;
1749 case SCTP_CMD_ADAPTATION_IND:
1750 sctp_cmd_adaptation_ind(commands, asoc);
1751 break;
1752 case SCTP_CMD_PEER_NO_AUTH:
1753 sctp_cmd_peer_no_auth(commands, asoc);
1754 break;
1755
1756 case SCTP_CMD_ASSOC_SHKEY:
1757 error = sctp_auth_asoc_init_active_key(asoc,
1758 GFP_ATOMIC);
1759 break;
1760 case SCTP_CMD_UPDATE_INITTAG:
1761 asoc->peer.i.init_tag = cmd->obj.u32;
1762 break;
1763 case SCTP_CMD_SEND_MSG:
1764 if (!asoc->outqueue.cork) {
1765 sctp_outq_cork(&asoc->outqueue);
1766 local_cork = 1;
1767 }
1768 sctp_cmd_send_msg(asoc, cmd->obj.msg, gfp);
1769 break;
1770 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1771 sctp_asconf_queue_teardown(asoc);
1772 break;
1773
1774 case SCTP_CMD_SET_ASOC:
1775 if (asoc && local_cork) {
1776 sctp_outq_uncork(&asoc->outqueue, gfp);
1777 local_cork = 0;
1778 }
1779 asoc = cmd->obj.asoc;
1780 break;
1781
1782 default:
1783 pr_warn("Impossible command: %u\n",
1784 cmd->verb);
1785 break;
1786 }
1787
1788 if (error) {
1789 cmd = sctp_next_cmd(commands);
1790 while (cmd) {
1791 if (cmd->verb == SCTP_CMD_REPLY)
1792 sctp_chunk_free(cmd->obj.chunk);
1793 cmd = sctp_next_cmd(commands);
1794 }
1795 break;
1796 }
1797 }
1798
1799 /* If this is in response to a received chunk, wait until
1800 * we are done with the packet to open the queue so that we don't
1801 * send multiple packets in response to a single request.
1802 */
1803 if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1804 if (chunk->end_of_packet || chunk->singleton)
1805 sctp_outq_uncork(&asoc->outqueue, gfp);
1806 } else if (local_cork)
1807 sctp_outq_uncork(&asoc->outqueue, gfp);
1808
1809 if (sp->data_ready_signalled)
1810 sp->data_ready_signalled = 0;
1811
1812 return error;
1813 }
Linux with added FPC-III support